Copper Oxides
Copper Oxide Thin Films on Au(111)
- Cu deposition in 10-5 mbar O2 on Au(111)
- Post-annealing in vacuum at temperatures between 450 and 700 K
- Water adsorption at 100 K probed via STM, TDS and IRAS
Copper Oxides
Film Morphology
- flat and homogenous films with Cu2O stoichiometry according to XPS
- Several terminations (hexagonal, stripes, donuts) at different annealing temperatures
- Dominant phase: hexagonal lattice with 6Å periodicity
Electronic properties
- Fundamental gap: 2.0 eV (smaller than bulk)
- Cu 4s surface state in unoccupied part of gap
- Surface state vanishes in CuCus-poor structures
Water Adsorption
- Zero order desorption at 155 K due to amorphous solid water
- First-order peak at 175 K from H2O monolayer
- → H2O physisorption to oxygen-terminated Cu2O(111) surface
Water Monolayer in STM
- Cyclic water clusters at low coverage
- Growth of monolayer H2O islands starting from step edges
- Short-ranged hexagonal order in H2O islands reflecting weak template effect of the Cu2O surface
For details:
Growth and Surface Properties of Cuprous Oxide grown on Au(111): Sträter et al. J. Phys. Chem. C 119 (2015) 5975.
Incorrect DFT- GGA predictions of the stability of non-stoichiometric/polar dielectric surfaces: The case of Cu2O(111): Nilius et al. PCCP 18 (2016) 6729.
Water Adsorption on Cu2O(111) Surfaces – An STM Study: Möller et al. J. Phys. Chem. C 121 (2017) 20877.
Temperature-Dependent Phase Evolution of Copper-Oxide Thin-Films on Au(111): Möller et al. Phys. Chem. Chem. Phys. 20 (2018) 5636